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Question 1
Incorrect
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Which of the following is caused by vitamin D?
Your Answer: Decreased plasma calcium
Correct Answer: Increased plasma phosphate
Explanation:Intestinal phosphate absorption is mediated by both transcellular and paracellular routes. The 1,25(OH)2D increases intestinal transcellular phosphate absorption at least in part by enhancing expression of type 2b sodium–phosphate cotransporter, thus increasing plasma phosphate.
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This question is part of the following fields:
- Clinical Sciences
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Question 2
Correct
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Which one of the following statements regarding nitric oxide is incorrect?
Your Answer: Promotes platelet aggregation
Explanation:Nitric oxide, known as an endothelium-derived relaxing factor (EDRF), is biosynthesized endogenously from L-arginine, oxygen, and NADPH by various nitric oxide synthase (NOS) enzymes and is a signaling molecule in many physiological and pathological processes in humans.
One of the main enzymatic targets of nitric oxide is guanylyl cyclase. The binding of nitric oxide to the haem region of the enzyme leads to activation, in the presence of iron. -
This question is part of the following fields:
- Clinical Sciences
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Question 3
Incorrect
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A woman with severe renal failure undergoes a kidney transplant. However, after a few hours, she develops fever and anuria. The doctors are suspecting hyperacute organ rejection. Which are the cells primarily responsible for hyperacute organ rejection?
Your Answer: Helper T Cells
Correct Answer: B Cells
Explanation:Hyperacute rejection appears in the first minutes following transplantation and occurs only in vascularized grafts. This very fast rejection is characterized by vessel thrombosis leading to graft necrosis. Hyperacute rejection is caused by the presence of antidonor antibodies existing in the recipient before transplantation. These antibodies induce both complement activation and stimulation of endothelial cells to secrete Von Willebrand procoagulant factor, resulting in platelet adhesion and aggregation. The result of these series of reactions is the generation of intravascular thrombosis leading to lesion formation and ultimately to graft loss. Today, this type of rejection is avoided in most cases by checking for ABO compatibility and by excluding the presence of antidonor human leukocyte antigen (HLA) antibodies by cross-match techniques between donor graft cells and recipient sera. This type of rejection is also observed in models of xenotransplantation of vascularized organs between phylogenetically distant species when no immunosuppressive treatment is given to the recipients.
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This question is part of the following fields:
- Clinical Sciences
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Question 4
Incorrect
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Cholecystokinin is secreted from:
Your Answer: K cells in upper small intestine
Correct Answer: I cells in upper small intestine
Explanation:Cholecystokinin (CCK) was discovered in 1928 in jejunal extracts as a gallbladder contraction factor. It was later shown to be member of a peptide family, which are all ligands for the CCK1 and CCK2 receptors. CCK peptides are known to be synthetized in the small intestinal endocrine I-cells and cerebral neurons.
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This question is part of the following fields:
- Clinical Sciences
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Question 5
Incorrect
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A 34-year-old man presents with haemoptysis and weight loss. History reveals he suffers from night sweats and upon auscultation you notice reduced breath sounds over the apex of his right lung and significant nail clubbing. You refer him to a pneumologist who administers the following antibiotics: rifampicin, ethambutol, pyrazinamide and isoniazid. What is the mechanism of action of the first drug?
Your Answer: Inhibit DNA synthesis
Correct Answer: Inhibit RNA synthesis
Explanation:Rifampicin specifically inhibits bacterial RNA polymerase, the enzyme responsible for DNA transcription, by forming a stable drug-enzyme complex with a binding constant of 10(-9) M at 37 C.
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This question is part of the following fields:
- Clinical Sciences
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Question 6
Incorrect
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Which one of the following statements regarding the normal distribution is correct?
Your Answer: Standard deviation = mean / square root (variance)
Correct Answer: Mean = mode = median
Explanation:Normal distribution, also known as the Gaussian distribution, is a probability distribution that is symmetric about the mean. The normal distribution has the following properties:
– It is symmetric around the mode, the median and the mean of the distribution.
– It is unimodal
– The area under the curve and over the x-axis is unity (i.e. equal to one).
– Its density has two inflection points.
– Its density is log-concave.
The standard deviation (SD) is a measure of how much dispersion exists from the mean. SD = square root (variance) -
This question is part of the following fields:
- Clinical Sciences
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Question 7
Incorrect
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Primarily, funnel plots are used to do what?
Your Answer: Provide a graphical representation of the relative risk results in a case-control study
Correct Answer: Demonstrate the existence of publication bias in meta-analyses
Explanation:Funnel plots are graphical tools to assess and compare clinical performance of a group of care professionals or care institutions on a quality indicator against a benchmark. Incorrect construction of funnel plots may lead to erroneous assessment and incorrect decisions potentially with severe consequences.
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This question is part of the following fields:
- Clinical Sciences
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Question 8
Incorrect
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A new blood test developed to screen individuals for cardiac failure was performed on 500 patients. The results were positive for 40 out of 50 patients with echocardiography-established heart failure. However, the test was also positive for 20 patients with no signs of heart failure. What is the positive predictive value of the test?
Your Answer: Cannot be calculated
Correct Answer: 0.66
Explanation:Positive predictive value = TP (true positives) / [TP + FP (false positives)] = 40 / (40 + 20) = 0.66
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This question is part of the following fields:
- Clinical Sciences
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Question 9
Incorrect
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A study is developed to look at the potential of hip protectors to reduce femoral neck fractures in elderly nursing home patients. The study included 800 patients randomly selected with an average age of 82 years of age. The data was collected over a two year period and the patients were randomly put in the standard care group or the hip protector group. From the 400 patients assigned to the hip protector group, 10 had a femoral neck fracture over the two year period. From the 400 patients assigned to the standard care group, 20 had a femoral neck fracture over the two year period. What is the correct value regarding the absolute risk reduction?
Your Answer:
Correct Answer: 0.025
Explanation:Absolute risk reduction (ARR) – also called risk difference (RD) – is the most useful way of presenting research results to help your decision-making. In this example, the ARR is 8 per cent (20 per cent – 12 per cent = 8 per cent). This means that, if 100 children were treated, 8 would be prevented from developing bad outcomes. Another way of expressing this is the number needed to treat (NNT). If 8 children out of 100 benefit from treatment, the NNT for one child to benefit is about 13 (100 ÷ 8 = 12.5). CER = 20 / 400 = 1 / 20 = 0.05, EER = 10 / 400 = 0.025, ARR =CER – EER = 0.025
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This question is part of the following fields:
- Clinical Sciences
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Question 10
Incorrect
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A 68-year-old male patient presents with haematemesis. Gastroscopy and biopsy reveal a carcinoma. Who is the one to inform the patient of his diagnosis?
Your Answer:
Correct Answer: The consultant in-charge of his care
Explanation:One of the questions the therapist poses himself while informing a patient is: whom shall I inform about the diagnosis, treatment and prognosis? If we unconditionally accepted the view that information belongs to the patient from an ethical and legal standpoint, we would automatically exclude the partner and the family. Therefore, the therapist should raise another question: what is the benefit to the patient? To answer the question and the resulting dilemma, we have to leverage the long experience of family therapy and tailor it to the cases we are dealing with. It should be taken into consideration that patient and family are a dynamic system which was balanced before the onset of the disease, but is now disrupted, entering into crisis. Therefore, the denial mechanisms and personality characteristics we have previously elaborated on, and communication among members play a crucial role in determining the information strategy and the way family should be approached. In this particular case, the most appropriate person to inform the patient is the consultant, meaning the one currently responsible for the patient’s care. The patient most probably has already developed some form of close and trustful relationship with his consultant.
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This question is part of the following fields:
- Clinical Sciences
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